While I don't have a ton of experience with live bearers.
- Leave the algea. It's a better nutruient soup than we could ever hope to provide. The fry also love playing/eating in light algea. Happier fry = faster fry.
- I've always gone crushed flake vs bbs / artemia, I tend to do ok. (In picky situations, I use a 12" length of cpvc 1/2" water pipe to feed them. Hard shake a 1/4 pinch of crushed flake in a 1/4 filled 20oz water bottle 'tank water' poured through the cpvc dumps soft ready food to the fry.) Not as fast as bbs, but it works. ^_^
- I feed as often as the fry will eat, while keeping an eye on water quality. (I tend to do the discus thing. Feed nonstop, change water nonstop_
- In my experience.... If you train fry to huge water changes and excellent feeding, they tend to forget they're supposed to be difficult fish.

(Not a constant, but a relevant.)
Fish, Hikari first bites are an excellent accepted starter. They're also $10+/lb. I don't deny they're awesome, but there are home brew means to keep the wrigglers happy. (IF the owner is stringent in quality / portion control.) It's a question of effort in almost all cases. More "well guided" effort lends to faster fish. ^_^